In the current edition of Epic, Space Marines are often run as an air assault army. Transports swoop in to drop off the marines directly into an engagement. Each Thunderhawk transport can carry 8 stands worth of power armored marines which could be an assault unit and a devastator unit, a tactical unit plus a dreadnought, or a terminator unit. For my classic Space Marine army I recently picked up 2 old style thunderhawks off of ebay.
These models are often called thunderbricks since they do not seem very aerodynamic. They are also quite small compared to there carrying capacity.
The models are three parts not including the flying stands. The body, the cannon, and the wing assembly. You can see how the wings join up with the body in these last two pictures.